Spatially Resolved Electrochemiluminescent Biosensor Combined with Nanopore Screening Devices for Simultaneous...

Improving the preprocessing efficiency and creating multiple detection channels are crucial for building high-performance sensors. In this study, we developed a sensing platform that integrates a spatially resolved electrochemiluminescence (ECL) biosensor with a nanopore screening device for the simultaneous detection of deoxynivalenol (DON) and aflatoxin B₁ (AFB₁) in wheat. Zeolitic imidazolate framework-67(ZIF-67), which promotes the production of oxygen radicals (O₂̇^-), was integrated with luminol-capped silver nanoparticles (Luminol-AgNPs) to function as an ECL probe for DON detection. CON₄H₆-Ru, synthesized by covalently linking tris(4,4'-dicarboxylicacid-2,2'-bipyridyl) ruthenium(II) dichloride [Ru(dcbpy)₃Cl₂] and carbonyldiazide (CON₄H₆), was encapsulated in mesoporous silica nanoparticles (MSNs) and used as another ECL probe for the detection of AFB₁. Subsequently, a reusable nanopore screening device was designed to eliminate macromolecular interference in the samples and improve the interference resistance of the sensing platform. Under the optimal experimental conditions, the sensing platform showed good linearity for DON concentrations from 0.005 to 150 μg/kg and AFB₁ concentrations from 0.05 to 100 μg/kg, with detection limits of 1.80 × 10^-4 and 1.09 × 10^-3 μg/kg (S/N = 3), respectively.